Device for extinction of electric arcs



Feb. 27; 1934. G =GE 1 ET AL 1,948,658

DEVICE FOR EXTINCTION OF ELECTRIC ARCS Filed July 7, 1930 2 Sheets-Sheet1 IllIl/IIII INS UL? 7706/ Feb. 27, 1934. G. GERIN ETAL- 1,948,658

DEVICE FOR EXTINCTION OF ELECTRIC ARCS Filed July 1 930 2 Sheets-Sheet 2Patented Feb. 27, 1934 UNITED STATES PJATENT OFFICE omen Gerln, swimApplication July Paul Joseph Branchu, and Tesmer, Grenoble, France I,1930, Serial No. 466,322

France July 9, 1929 4 Claim.- (Cl. 200-144) This invention relates to adevice for extinguishing electric arcs and to the use of this device foropening an electric circuit.

Its first object is to provide means to deaden the arc in the interiorof an interrupting chamber or close to the same, by forcing the arc toenter a chamber, which is formed by a central electrode and an outerelectrode and metallic rods or pieces which are insulated relatively toeach other, and are interposed between these terminal electrodes andform the intermediary electrodes for the purpose of cooling the same,and of subdividing the arc or rupture into a plurality of serial arcs.Another object is to provide means for blowing out the arc and adaptedto elongate the arc and impart to the are a rotary movement and forcethe arc to assume the shape of a spiral or a conical spiral.

Another object is to provide metallic parts corresponding to the formwhich the arc assumes when being rotatably displaced, and to assure thegradual increasing subdivision of the arc while it is beingsimultaneously elongated.

Another object is to so dimension and space said metallic parts as toassure a uniform distribution of the potential within the gap comprised,

between the two electrodes.

Another object is to interpose between the terminal electrodes andbetween the metallic parts serving as intermediary. electrodes,insulating parts forming segments of circles separated from each otherand arranged concentrically in order to break certain parts of the arcand to amplify its elongation.

In the drawings Figure 1 is a vertical central section of an interrupterconstructed and arranged in accordance with this invention.

Figure 1 is a detail transverse sectional view oi the lever h]. andlever '1 and their connections.

Figure 2 is a section of the same on line 2-2 of Figure 1.

Figure 3 is a similar section of a modification.

Figure 4 is a diagram of the electric circuit.

Figure 5 is a detail sectional view of mechanism for actuating theshunting contacts.

The circuit interrupter shown in Figure 1 is composed primarily of abase socket S on which are fixed by means of insulators 1, four posts Cwhich carry the device for extinguishing the arc. This comprises aconical mass g of insulating material supported by the posts C. Saidelement a extends across and closes the upper end or an extinguishingchamber, the wall of which is formed by a metallic cylinder 0 on whichis wound the coil d constituting the blowout coil, which is connected onthe one hand with the cylinder c and on the other hand with the clamp s,as shown in Figure 4.

In the center of the mass q is also fixed a core e1 which carries aconducting tube e, which tube serves as the main fixed contact. A brush62 mounted at the lower end of said tube e. Said tube forms the firstelectrode of the chamber a for extinguishing an are produced in thecenter 65 of the cylinder 0.

The core e1 is located in the center of an opening j in the part a,which opening serves as a draft chimrie y for cooling the apparatus andfor improving in this manner the heat conditions.

Movable contacts h and i mounted on a lever hl contact with the tube eand the brush ez respectively.

The first portion h: of this lever which extends up to the level of thecontact e:, is formed of two metallic jaws in (Fig. 5). The secondportion is composed of a metallic member ha separated from the jaws i bythe insulating blades he. This member In is cranked or bent at its innerend and constitutes a first auxiliary contact k.

The lever hi is freely pivoted about a shaft hi carried by bearingswhich are arranged within a frame hs fixed on the columns C by means ofrings or collars.

The lever hi is controlled by a link rod A1 of a5 insulating materialand a metallic handle A2, which is pivotally mounted as shown.

Another lever 7'1 is keyed on .the shaft hi and carries the secondauxiliary contact a which is adapted to engage the first auxiliarycontact k, carried by the lever hi. These two auxiliary contacts servefor short circuiting the blowout coil d.

The lever hi may turn freely about the shaft hi while the lever 1'1turns with the shaft hand it is advisable to slightly brake the same toavoid that the lever ii should be carried along at the beginning of themovement of the lever ht. The lever a": is braked by blocking the sameagainst the surface of the bearing by means of the small 1im ring washer7'5 (Fig. 5).

On this last named lever hi there is fixed an abutment he adapted tocome into interhook engagement with another abutment :iz fixed'on thelever 7'1 when the lever hi is slightly actuated.

Stops h! and a: are fixed on the frame h.- and are offset in such mannerthat at the end of the stroke of the levers hi and ii. the auxiliarycontact between i and]: remains open as shown by no the positions ottheleversindottedlinesinl'ig- The auxiliary contact iis connected with thejaws h: 01' the lever through a shunt is.

The extinguishing device is completed by rods b, the upper ends 01'which are embedded in the insulating mass 0.

In one embodiment shown in Figure 2, the said rods are-arrangedspirally. In the same figure there is shown a form 01' arcalso of spiralshape at:r,and itwillbeseenthzitinthiscasathe number of small arcsserially aligned between certain of the rods 1) which constitute-thepath of the entire arc is considerably greater than it theentirearcextendedintheiorm of anordinarystraightrayiromctoc.

Such of the rods as are arranged in concentric circles form a series ofcondensers which are connected in cascade form. The capacities 0! thesecondensers may either be made equal through proper selection of thedimensions or the rods, or they may be equalized by proper selection 01'their number, assuring a uniform distribution of the electrostaticpotential between the terminal electrodes e, c.

Figure 3 shows another embodiment of the arc extinguishing chamber wherein addition to the metallic rods 21, there are provided concentricallyarranged arcuate insulating partition walls t1, ta, ta,Inthiscase,theiormotthearc assumedby the latter at one instantwhile itis being shifted, willbethat form whichisshowniniulllines at 1Theshapeoithespiralarczwith which it may be compared is shown in dottedlines.

The means for moving the contacts may be of any suitable construction.For the purposes of this specification suitable mechanism for thispurpose is shown in Figure 5. and comprises an auxiliary contact 1'which is imder frictional control of a spring m locked by the nut a andthereby locking the lever is against the bracket ha.Itwillusuallyremainstationaryaslongasitisnotactuatedbythetappethwhichismounted on the extension of the leverha. 1

As shown by the electric wiring diagram, Figures 1 and 4, the currentwhen the circuit is closed passes through the central tube e and theprincipal contacts 2: and i, and leaves through conductor i1 and thebushing s. 11', however, the brushes are opened, the current passesthrough the spark protectors e and h and through the conductors in andauxiliary contacts I: and i which are arrangedior shortcircuitingthecoild so as to deprive the coil of current. When, however, these also areopened, the current passes through the spark protectors c and it throughthe conductor (1: and through the blowout coil d, conductor d andbushing In all cases the spark protectors h are always insulated withrespect to the principal contact e: because the lever which carries itis formed of two parts In and Ila-which are insulated from each other. I

The operation of the device is extremely simple and will readily beunderstood. The destruction of thearctakesplacebetweenthecentral rodeand the spark protector h, after the principal contacts ed and i havebeen opened. This are is subjected to an electrodynamic blow produced bythe coil d after the short circuit of the latter has been relievedthrough the auxiliary contacts and k.

The operation of the auxiliary contact calls for some further statement.The contacts I: are

displaced with the leverju while the contact 1 is displaced with thelever i1, and lags, for it is not actuated directly. It is advisable tomake surethatthislagging eflectashas beenstated above, should beproduced by a supplementary friction engagement for slowing down therotation of the shaft '14- Owing to this condition, the auxiliarycontacts 1', k are open after a very short stroke of the lever hi.However, the lever '1 is operated by means of abutments he, 1: which arefixed on the levers hr and 7'1 respectively. At the end of the stroke ofthe lever hi the auxiliary contacts 11'): remain open owing to thedisengagement of the stop abutments h: and 7'; correspondingrespectively to the levers hi and 7'1. The opening pomtion is shown indotted lines.

It will be understood that upon closure of the lever hr the auxiliarycontacts a, k are closed immediately and that the electrodynamic blowoutbecomes effective only on the extinguishing spark. Upon closure thelever 71 resting originally in stationary condition and the lever h:

short-circuited and it has no eflect on the are. which will beextinguished between the lightning arresters h, e.

When under the sheet of this electrodynamic blowout produced by the coild, the arc is deformed, producing hence a band which is prolonged andwhich very rapidly'reaches the cylinder c. At this instant the arc Jumpsapproximately in radial direction between e and c.

. On the other hand, the convolutions of the coil being axial,- the arenecessarily must be shifted on a circular path by turning about thecentral rod e. During this rotary movement, it upin thetormotaspiraloroia conical spiral, a form which corresponds to the dynamiccurve of equilibrium.

"As the arc gets gradually longer, its breakingupintosmallpartsalsobecomesgraduallymore pronounced.

Finally, it between the end electrodes not onlythemetallicrodsbareinthepath,butalso insulating partition walls t1, ta,is, there is produced an amplification ot the elongated are as indicatedin Figure 3 at v and this elongation also gradually increases. In thiscase, however, the breaking-up does not proceed quite that far and forthis reason, this device itself is not applied as often as when there isobtained an elongation of the arc sumcient to make sure the cutting oithe are under a predetermined intensity and a certain voltage.

By the use of metallic rods, combined with the rotary movement of theare into spiral shape, it will be seen that in the same scope or i'rame,there may be produced a much greater length of arc than that whichcorresponds to the distance between the electrodes, and, therefore, itis ieasible to interpose in its path, a number of electrodes ofintermediary character and this number is much greater than the numberwhich could beappliedtothe ordinarypathoithearcinthsbreakageotadeviceoithischaracterisdependent upon the increase elongatingthe arc, cutting ofl. the arc, which is practically more important thanthat with the devices heretofore employed by means or the interrupter ofgmt power and small dimensions.

inbreakingupand we have obtained a power of The essential advantage orthe device forming m the subject of the present invention with respectto what is known in this line, is that the elongation of the areobtainable while it is rotatively displaced, is a very great one withoutmaking necessary the provision of an interrupting chamber havingextremely large dimensions for this purpose. The arc is elongated moreand more in proportion to the degree of its rotary displacement.Furthermore, due to the combination described, there is producedsimultaneously with the subdivision of the arc due to the interpositionof intermediatelyelectrodes between the terminal electrodes,intermediary electrodes, it results that the breakage should be more andmore abrupt in proportion to the elongation of the arc, due to the factof such elongation and also to the arrangement of the intermediaryelectrodes.

What we claim, is:

1. In a device for extinction of an electric are. a chamber for therupture of the arc having a conducting wall forming a first electrode, asecond electrode in said chamber to produce an are between same and thewall of the chamber, a blowout coil on said first electrode producing anaxial field in the space between the said two electrodes, one electrodeenveloping the other and the length of the arc path for one revolutionof the are being greater on one electrode than the other, so that thepath traversed by the are at one turn under the eflfect of the blowoutfield is greater on the enveloping electrode than on the envelopedelectrode, and is spiral.

2. In a device for extinction of an electric arc, a cylinder to form anarc-breaking chamber and having a wall forming one electrode or the are,

a central fixed contact, a movable contact, means to close and to opensaid contacts, windings around said cylinder, means to energize saidwindings while the said contacts are in opened position, and means insaid cylinder between said fixed contact and said wall for elongatingthe spiral arc resulting from the electrodynamic blow produced by thewindings after the short circuit of the latter has been relieved.

3. In a circuit breaker, an arc-rupture chamber, comprising a conductingwall forming an electrode and an insulating mass extend-- ing across thechamber at one end of said wall, metal rods arranged in said chamber toefiect distribution of the electro-static potential in said chamber, oneend of each of said rods being embedded in said insulating mass, saidinsulating mass having a central opening, fixed contacts, a central rodto support the fixed contacts and to form one electrode of the arc, andwindings around said wall of said chamber, to ensure the electrodynamicblasting and the winding up of the arc in the shape of a spiral line. 4.In a circuit breaker, an arc-rupture chamber, a central rod, thereinforming one electrode, insulating tubular partitions in the said chamberarranged to provide tortuous paths to amplify the elongation of the arc,and means to create an electrodynamic field in said chamber and tospirally force the are around said elec trode rod.

GASTON. GERIN.

PAUL JOSEPH BRANCHU.

STANISLAS TESZNER.

